#!/usr/bin/env python
#_*_ coding: utf-8 *_*
'''
Created on 4 feb. 2010

@author: ??
http://ubuntuforums.org/showthread.php?t=500337
'''
## various attributes of the capture, and reads in a loop,
## Then prints the volume.
## To test it out, run it and shout at your microphone:
#http://pyalsaaudio.sourceforge.net/libalsaaudio.html

import alsaaudio, time, audioop, alsatryout

# Open the device in nonblocking capture mode. 
# The last argument could just as well have been zero for blocking mode. 
# Then we could have left out the sleep call in the bottom of the loop
inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NONBLOCK)

# Set attributes: Mono, 8000 Hz, 16 bit little endian samples
inp.setchannels(1)
inp.setrate(8000)
inp.setformat(alsaaudio.PCM_FORMAT_S16_LE)

# The period size controls the internal number of frames per period.
# The significance of this parameter is documented in the ALSA api.
# For our purposes, it is sufficient to know that reads from the device
# will return this many frames. Each frame being 2 bytes long.
# This means that the reads below will return either 320 bytes of data
# or 0 bytes of data. 
# The latter is possible because we are in nonblocking mode.
inp.setperiodsize(160)

while True:
    # Read data from device
    l,data = inp.read()
    if l:    
        # Return the maximum of the absolute value of all samples in a fragment.
        print audioop.max(data, 2)
        if (audioop.max(data, 2) > 2000):
            alsatryout.bipe()
    time.sleep(.001)
